Intumescent Pad Attached to Back of Outlet Box Molded In Test Cap for Testing of DWV Drain System - Test Cap Will Not Fall Down the Drain Snap-On Frame Accommodates two 5/8" Drywall Simple Installation-Just Nail or Screw to Stud Preloaded Nails for Right or Left Stud Bay Installation Warnock Hersey Certified 1hr & 2hr Rated Made of High Temperature Resin No Special Wrapping or Sheet Rock Fabrication Needed